WHAT IS COMPOST?
Compost is produced when organic matter, such as garden and lawn waste,
is broken down by bacteria and fungi. When added to soil it improves soil
structure; sandy soils will hold water better while clays will drain faster.
Compost also promotes a biologically healthy soil by providing food for
earthworms, soil insects, and beneficial microorganisms.
When you purchase compost, buy it from a reliable source. Large-scale commercial
composting is a controlled, high-temperature process that destroys weed
seeds and disease organisms, and produces a relatively sterile product.
You can also make your own compost with yard and kitchen wastes (see the
Texas Agriculture Extension Service manual Don't Bag It-Compost It for the
Compost contains micronutrients beneficial to plant health, but is not considered
to be a fertilizer as it is low in nitrogen, phosphorus, and potassium.
The amount of nitrogen in compost is low compared to organic materials,
such as manure. Since nitrogen in the plant waste is lost during the composting process,
some nitrogen is also incorporated into organic compounds and released slowly
after the compost is applied to the soil.
COMPOST BENEFITS THE ENVIROMENT
Compost contains an organic material called humus which assists the soil
in holding nutrients. Humus lessens the need for chemical fertilizers and
helps prevent leaching of nitrogen into groundwater. Humus-rich soil also
promotes healthy plants which are less susceptible to diseases and insect
pests. This can reduce the need for chemical pesticides.
Compost reduces erosion by improving soil structure. Better drainage allows
water to flow into lower soil layers, rather than puddle on top and run
off. Improved soil structure also helps the growth of roots which hold soil
in place. Finally, compost recycles garden wastes to benefit the enviroment.
Compost can be used to make a good container gardening medium. First, strain
the compost through a sieve to eliminate large particles. Then mix two parts
compost, one part garden loam, and one part perlite or sand. Add a tablespoon
each of phosphate and potash for each pot of mixture. You can also substitute
compost for peat moss in other suggested potting mixtures.
Vegetable and Flower Gardening
If you produce large amounts of compost, spread about 2 inches over your
entire garden annually and work it 6 to 8 inches into the soil. More than
2 inches at one time may encourage grubs. As an alternative to compost,
you can till 3 to 4 inches of shredded, uncomposted leaves into your garden
or flower bed in the fall. The leaves will decompose during winter and enrich
the soil. If your supply of compost is small, use it with transplants. Dig
the hole for your transplant and mix a trowel of compost into the backfill.
The compost will loosen the soil for the young plant's roots and also provide
it with micronutrients.
Compost is not as effective for a mulch, as weed seed tends to grow rapidly
The purpose of intensive gardening is to harvest the most produce possible
from a given space. The key to its success is fertile soil, high in organic
matter. Humus-rich compost holds extra nutrients in the soil that might
otherwise be leached out. It provides food for earthworms and beneficial
microorganisms, and allows for deep root penetration, permitting closer
spacing of plants.
Raised beds are basic to intensive gardening. You can create a raised bed
by first mixing 2 inches of compost with the top 6 to 8 inches of garden
soil. Then build beds by mounding soil from the pathways into raised beds
approximately 8 to 12 inches high and 3 to 4 feet wide. Heavily mulch the
pathways with wood chips to eliminate weeds. Repeat this every year. Or
build wooden frames around the beds to make them permanent and enrich the
contained soil with compost annually.
Shrubs and Trees
Add compost to the soil around your shrubs and trees. In late spring, place
about 1 inch of compost around the plants. Cover this with a mulch of shredded
pine needles, straw, bark chips, or leaves 2 to 3 inches deep. The humic
acid from the compost and decomposing mulch will penetrate the soil and
change its structure. This will improve the moisture retention, aeration
and fertility of the soil.
Incorporating compost into soil is an excellent way to establish or renovate
a lawn. Spread about 2 inches of compost over the planned lawn area. Till
this into the soil before laying turf or planting grass seed. Do not spread
compost on an established lawn, as this may cause thatch buildup which can
lead to disease, insect problems, and temperature and drought stress.
For more information on selection, planting, cultural practices, and enviromental
quality, contact your local Texas Agricultural Extension Service. If you
want to learn more about horticulture through training and volunteer work,
ask your Extension agent about becoming an Extension Master Gardener. For
further information write to Department of Horticultural Sciences, Hor/For-225,
Texas Agricultural Extension Service, College Station, Texas 77843.
Copyright 1992. Original manuscript by the Virginia Cooperative Extension
Service and the Department of Horticulture at Virginia Polytechnic Institute
and State University. Adapted for use in Texas by Marty L. Baker, Associate
Professor and Extension Horticulture Specialist, Department of Horticultural
Sciences, and Robert Burns, Extension Communications Specialist, Department
of Agricultural Communications.
Texas Agricultural Extension Service
Texas A&M University System